Repeat Problem 15-7 for a double-dwell cam to move the roller follower from 0 to 2 inches in 45° with cycloidal motion, dwell for 150°, fall2 inches in 90° with modified sine motion, and dwell for the remainder. Cam speed is 200 rpm. Choose a suitable r spring rate and preload to maintain follower contact. Select a spring from Appendix D. Assume a damping ratio of0.15.
Problem 15-7.
Figure Pl5-l shows a cam-follower system. The dimensions of the solid, rectangular 2 X 2.5 in cross-section aluminum arm are given. The cutout for the 2-in-diameter , 1.5-in-wide steel roller follower is 3 in long. Find the arm mass, center of gravity location, and mass moment of inertia about both its CG and the arm pivot. Create a linear, one-DOF lumped mass model of the dynamic system referenced to the camfollower and calculate the cam-follower force for one revolution. The cam is a pure eccentric with eccentricity = 0.5 in and turns at 500 rpm. The spring has a rate of 123 lb/in and a preload of 173 lb. Ignore damping.